Type Equivalence, Subtyping, and Type Transformations in Object-oriented Databases Type Equivalence, Subtyping, and Type Transformations in Object-oriented Databases
نویسنده
چکیده
In this report, a number of completeness results are given that are useful for database integration on the schema level and the instance level. Type equivalence and subtyping are proven sound and complete w.r.t. a model-theoretic semantics. Furthermore, a set of type transformations is introduced that is proven sound and complete w.r.t. data capacity. These completeness results imply that if database schemas are integrated using type equivalence, subtyping, and the set of type transformations, then their instances can be integrated as well.
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